1. Field of the Invention
The invention generally relates to load balancing in wireless communications, and more particularly, to prioritized load balancing using priority levels of users.
2. Description of the Related Art
Due to communication technology advancements in recent years, several mobile communication technologies, such as Wideband Code Division Multiple Access (W-CDMA) technology, 1×Code Division Multiple Access 2000 (1×CDMA 2000) technology, 1×Evolution-Data Optimized (1×EVDO) technology (or otherwise called a 1×High Rate Packet Data (1×HRPD) technology), and Long Term Evolution (LTE) technology, etc., have been developed to provide high data communicating rates. In a service network, an access network (AN) is equipped with an antenna, serving as a cell of the mobile communication system. An access terminal (AT) transceives radio signals from the AN to obtain data communication services. The AN may be connected to a mobile switching system which is further connected to a telephone/data network. The AN converts RF signals to telephonic/data signals, and vice versa, to allow communication between the AT and other communication terminals somewhere else in the telephone/data network. The coverage areas of multiple ANs may overlap in order to ensure that an AN is selected to provide communication services to the AT. Since there are multiple ANs with concurrent required services, the mobile switching system must determine which AT will provide services to the AT. In a conventional mobile communication system, the AN chosen, is determined by comparing the signal strength of signals between the AT and each involved AN. Generally, the AN with the strongest signal strength is assigned to provide communication services to the AT.
However, there may be situations where many ATs flock into the coverage of an AN, or many ATs flock from one service network to another, or all ATs in the coverage of an AN request high bandwidth usage from the AN, which cause an overload of the flocked AN or the flocked service network, and results in rejected requests to any new ATs in the same area. Thus, in order to avoid ping-pong effect and increase the system stability of the service networks, it is preferred to have the loading of a service network evenly distributed among the ANs and limit the amount of ATs that are transferred to another service network. Meanwhile, it is also desirable to serve all ATs in such a way that good performance can be achieved for the ATs and the service network.